U.S. patent number 4,618,557 [Application Number 06/763,112] was granted by the patent office on 1986-10-21 for liquid developer for electrostatic photography.
This patent grant is currently assigned to Fuji Photo Film Co., Ltd.. Invention is credited to Shigeyuki Dan, Kazuo Ishii, Eiichi Kato, Hidefumi Sera.
United States Patent |
4,618,557 |
Dan , et al. |
October 21, 1986 |
Liquid developer for electrostatic photography
Abstract
An liquid developer for electrostatic photography is described,
comprising a carrier liquid having an electric resistance of at
least 10.sup.9 .OMEGA..multidot.cm and a dielectric constant of not
more than 3.5, and a resin dispersed therein, said resin being
obtained by polymerizing a monomer, which is soluble in said
carrier liquid but becomes insoluble upon being polymerized, in the
presence of at least one kind of a soluble dispersion stabilizing
resin, said soluble dispersion stabilizing resin being a copolymer
containing at least recurring units represented by following
formulae (IIIa) and (IIIb) obtained by applying a reaction for
introducing an unsaturated bond into a copolymer obtained by
polymerizing a monomer represented by formula (I) and a monomer
represented by formula (III) ##STR1## wherein in formula (I), V
represents --O--, --S--, --CO--, --CO.sub.2 --, --SO.sub.2 --,
--OCO--, --CONH--, --CONR'-- (wherein R' represents a hydrocarbon
group), --NHCO--, NHCO.sub.2 --, or --NHCONH--; X represents
--CO.sub.2 H, --COCl, --OH, --SH, --NH.sub.2, --NCO, or --SO.sub.2
CH.sub.2 CH.sub.2 Cl; W represents a hydrocarbon group linking said
atomic group V and said atomic group X directly or through a hetero
atom, or W represents a chemical bond; and a.sub.1, a.sub.2, and
a.sub.3 each represents a hydrogen atom, a hydrocarbon group, a
carboxy group, or a carboxy group through a hydrocarbon group; in
formula (II), Y represents --O--, --S--, --CO--, --CO.sub.2 --,
--SO.sub.2 --, --OCO--, CONH--, --CONR"-- (wherein R" represents a
hydrocarbon group), --NHCO--, --NHCO.sub.2 --, or --NHCONH--; R
represents a hydrocarbon group; and b.sub.1, b.sub.2, and b.sub.3
each represents a hydrocarbon atom, a hydrocarbon group, a carboxy
group, or a carboxy group through a hydrocarbon group; in formula
(IIIa), a.sub.1, a.sub.2, a.sub.3, V, and W have the same meanings
as defined for formula (I); X' represents --CO.sub.2 --, --COS--,
--SCO--, --CONH--, --OCO--, --NHCO--, --NHCONH--, --SO.sub.2 --,
--O--, or --S--; Z represents a hydrocarbon group linking said
atomic group X' and unsaturated bond directly or through a hetero
atom, or Z represents a chemical bond; the total number of atoms of
the main chain portion of atomic group --V--W--X'--Z-- must,
however, be at least 9; and d.sub.1, d.sub.2, and d.sub.3 each
represents a hydrocarbon atom, a hydrocarbon group, a carboxy
group, or a carboxy group through a hydrocarbon group; and in
formula (IIIb), b.sub.1, b.sub.2, b.sub.3, Y, and R have the same
meanings as defined for formula (II).
Inventors: |
Dan; Shigeyuki (Kanagawa,
JP), Ishii; Kazuo (Kanagawa, JP), Kato;
Eiichi (Kanagawa, JP), Sera; Hidefumi (Kanagawa,
JP) |
Assignee: |
Fuji Photo Film Co., Ltd.
(Kanagawa, JP)
|
Family
ID: |
15805651 |
Appl.
No.: |
06/763,112 |
Filed: |
August 7, 1985 |
Foreign Application Priority Data
|
|
|
|
|
Aug 7, 1984 [JP] |
|
|
59-165088 |
|
Current U.S.
Class: |
430/114; 430/115;
430/137.17; 430/137.22 |
Current CPC
Class: |
G03G
9/131 (20130101) |
Current International
Class: |
G03G
9/13 (20060101); G03G 9/12 (20060101); G03G
009/12 () |
Field of
Search: |
;430/114,115,137 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Welsh; John D.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak, and
Seas
Claims
What is claimed is:
1. A liquid developer for electrostatic photography comprising a
carrier liquid having an electric resistance of at least 10.sup.9
.OMEGA..multidot.cm and a dielectric constant of not more than 3.5,
and a resin dispersed therein, said resin being obtained by
polymerizing a monomer, which is soluble in said carrier liquid but
becomes insoluble upon being polymerized, in the presence of at
least one kind of a soluble dispersion stabilizing resin, said
soluble dispersion stabilizing resin being a copolymer containing
at least recurring units represented by following formulae (IIIa)
and (IIIb) obtained by applying a reaction for introducing an
unsaturated bond into a copolymer obtained by polymerizing a
monomer represented by formula (I) and a monomer represented by
formula (II) ##STR6## wherein in formula (I), V represents --O--,
--S--, --CO--, --CO.sub.2 --, --SO.sub.2 --, --OCO--, --CONH--,
--CONR'-- (wherein R' represents a hydrocarbon group), --NHCO--,
NHCO.sub.2 --, or --NHCONH--; X represents --CO.sub.2 H, --COCl,
--OH, --SH, --NH.sub.2, --NCO, or --SO.sub.2 CH.sub.2 CH.sub.2 Cl;
W represents a hydrocarbon group linking said atomic group V and
said atomic group X directly or through a hetero atom or W
represents a chemical bond; and a.sub.1, a.sub.2, and a.sub.3 each
represents a hydrogen atom, a hydrocarbon group, a carboxy group,
or a carboxy group through a hydrocarbon group;
in formula (II), Y represents --O--, --S--, --CO--, --CO.sub.2 --,
--SO.sub.2 --, --OCO--, CONH--, --CONR"-- (wherein R" represents a
hydrocarbon group), --NHCO--, --NHCO.sub.2 --, or --NHCONH--; R
represents a hydrocarbon group; and b.sub.1, b.sub.2, and b.sub.3
each represents a hydrogen atom, a hydrocarbon group, a carboxy
group, or a carboxy group through a hydrocarbon group;
in formula (IIIa), a.sub.1, a.sub.2, a.sub.3, V, and W have the
same meanings as defined for formula (I); X' represents --CO.sub.2
--, --COS--, --SCO--, --CONH--, --OCO--, --NHCO--, --NHCONH--,
--SO.sub.2 --, --O--, or --S--; Z represents a hydrocarbon group
linking said atomic group X' and unsaturated bond directly or
through a hetero atom, or Z represents a chemical bond; the total
number of atoms of the main chain portion of atomic group
--V--W--X'--Z-- must, however, be at least 9; and d.sub.1, d.sub.2,
and d.sub.3 each represents a hydrogen atom, a hydrocarbon group, a
carboxy group, or a carboxy group through a hydrocarbon group;
and
in formula (IIIb), b.sub.1, b.sub.2, b.sub.3, Y, and R have the
same meanings as defined for formula (II).
2. A liquid developer for electrostatic photography comprising a
carrier liquid having an electric resistance of at least 10.sup.9
.OMEGA..multidot.cm and a dielectric constant of not more than 3.5
and a colored resin dispersed therein, said colored resin being a
colored copolymer resin obtained by the following procedure (1) and
(2):
(1) a resin dispersion is prepared by polymerizing a monomer, which
is soluble in said carrier solvent but becomes insoluble upon being
polymerized, in the presence of a copolymer, as a soluble
dispersion stabilizing resin, containing at least recurring units
represented by formulae (IIIa) and (IIIb) obtained by applying a
reaction for introducing an unsaturated bond into a copolymer
obtained by polymerizing a monomer represented by formula (I) and a
monomer represented by formula (II); ##STR7## wherein in formula
(I), V represents --O--, --S--, --CO--, --CO.sub.2 --, --SO.sub.2
--, --OCO--, --CONH--, --CONR'-- (wherein R' represents a
hydrocarbon group), --NHCO--, NHCO.sub.2 --, or --NHCONH--; X
represents --CO.sub.2 H, --COCl, --OH, --SH, --NH.sub.2, --NCO, or
--SO.sub.2 CH.sub.2 CH.sub.2 Cl; W represents a hydrocarbon group
linking said atomic group V and said atomic group X directly or
through a hetero atom or W represents a chemical bond; and a.sub.1,
a.sub.2, and a.sub.3 each represents a hydrogen atom, a hydrocarbon
group, a carboxy group, or a carboxy group through a hydrocarbon
group;
in formula (II), Y represents --O--, --S--, --CO--, --CO.sub.2 --,
--SO.sub.2 --, --OCO--, --CONH--, --CONR"-- (wherein, R" represents
a hydrocarbon group), --NHCO--, NHCO.sub.2 --, or --NHCONH--; R
represents a hydrocarbon group; and b.sub.1, b.sub.2, and b.sub.3
each represents a hydrogen atom, a hydrocarbon group, a carboxy
group or a carboxy group through a hydrocarbon group;
in formula (IIIa), a.sub.1, a.sub.2, a.sub.3, V and W have the same
meanings as defined for formula (I); X' represents --CO.sub.2 --,
--COS--, --SCO--, --CONH--, --OCO--, --NHCO--, --NHCONH--,
--SO.sub.2 --, --O-- or --S--; Z represents a hydrocarbon group
linking said atomic group X' and unsaturated bond directly or
through a hetero atom, or Z represents a chemical bond; the total
number of atoms of the main chain portion of atomic group
--V--W--X'--Z-- must, however, be at least 9; and d.sub.1, d.sub.2,
and d.sub.3 each represents a hydrogen atom, a hydrocarbon group, a
carboxy group, or a carboxy group through a hydrocarbon group;
and
in formula (IIIb), b.sub.1, b.sub.2, b.sub.3, Y and R have the same
meanings as defined for formula (II);
(2) the colored copolymer resin is produced by adding at least one
kind of an organic dye into the resin dispersion obtained in
above-described method (1) and heating the mixture.
3. The liquid developer as claimed in claim 1, wherein the monomer,
which is soluble in the carrier liquid but becomes insoluble upon
being polymerized, is a substance represented by the following
formula (IV), itaconic anhydride, maleic anhydride,
vinylpyrrolidone, and acrylonitrile. ##STR8## wherein e.sub.1,
e.sub.2 and e.sub.3 each represents a hydrogen atom, a hydrocarbon
group having 1 to 4 carbon atoms, a carboxy group, or a carboxy
group through a hydrocarbon group; L represents a hydrocarbon atom
having 1 to 2 carbon atoms, or L represents a chemical bond; M
represents --CO.sub.2 --, --OCO--, or --O--; and N represents a
hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms, or a
hydroxyl group through a hydrocarbon group.
4. The liquid developer as in claim 1, wherein the carrier liquid
is an unsubstituted or halogen-substituted straight-chain or
branched-chain aliphatic hydrocarbon.
5. The liquid developer as in claim 2, wherein the carrier liquid
is an unsubstituted or halogen-substituted straight-chain or
branched-chain aliphatic hydrocarbon.
6. The liquid developer as in claim 2, wherein the heating is
conducted at a temperature of from 40.degree. C. to 150.degree. C.
for a period of from 30 minutes to 12 hours.
7. The liquid developer as in claim 2, wherein the heating is
conducted at a temperature of from 80.degree. C. to 150.degree. C.
for a period of from 1 hour to 5 hours.
8. The liquid developer as in claim 2, wherein the amount of dye is
3% by weight or more with respect to the weight of the resin
particles in the dispersion.
9. The liquid developer as claimed in claim 2, wherein an organic
solvent capable of swelling the monomer or resin is used in the
procedure (1).
10. The liquid developer as claimed in claim 9, wherein the organic
solvent is used in an amount of about 0.1 to 10 times the weight of
the resin particles in the dispersion.
Description
FIELD OF THE INVENTION
This invention relates to a liquid developer for electrostatic
photography comprising at least a resin dispersed in a carrier
liquid having an electric resistance of at least 10.sup.9
.OMEGA..multidot.cm and a dielectric constant of not more than 3.5.
More particularly, the invention relates to a liquid developer
excellent in redispersibility, shelf life, stability, and
fixability.
BACKGROUND OF THE INVENTION
An ordinary liquid developer for electrostatic photography is
generally prepared by dispersing organic or inorganic pigments or
dyes, such as carbon black, Nigrosine, Phthalocyanine Blue, etc.,
and a natural or synthetic resin such as an alkyd resin, an acrylic
resin, rosin, a synthetic rubber, etc., in a high-insulating and
low-dielectric constant liquid such as a petroleum aliphatic
hydrocarbon and further adding thereto a polarity controlling agent
such as a polymer containing a metal soap, lecithin, linseed oil, a
higher fatty acid, vinyl-pyrrolidone, etc. In such a liquid
developer, a resin is dispersed therein as insoluble latex
particles having diameters of several .mu.m to several hundred
.mu.m, and since, in a conventional liquid developer, the bonding
between a soluble dispersion stabilizing resin or a polarity
controlling agent and insoluble latex particles is insufficient,
the soluble dispersion stabilizing resin and the polarity
controlling agent are in a state of easily diffusible in the
liquid. Accordingly, in such a conventional liquid developer, there
is a disadvantage that the soluble dispersion stabilizing resin is
released from the insoluble latex particles by the storage of the
developer for a long period of time or by repeated use of the
developer, the cause precipitation, aggregation, or accumulation of
the latex particles, whereby the polarity of the liquid developer
becomes obscure. Also, since the latex particles, once aggregated
or accumulated, are difficult to disperse again, the particles
stick to various portions of a developing devince to cause strains
of images formed as well as problems of the developing device, such
as clogging of a liquid supply pump, etc.
For eliminating these disadvantages, a means for chemically bonding
the soluble dispersion stabilizing resin and the insoluble latex
particles is disclosed in U.S. Pat. No. 3,990,980.
However, the improvement for the redispersibility, the shelf life,
and stability of the liquid developer was insufficient, and the
latex particles precipitated or accumulated at various portions of
a developing device were solidified in film-form and were difficult
to redisperse in the means disclosed in aforesaid U.S. Pat. No.
3,990,980. Also, the particles prepared by the above-described
means have two or more peaks in the particle size distribution
curve or a broad particle size distribution, and it was difficult
to control the particle size of the particles. Thus, the liquid
developer containing the particles was also poor in shelf life and
stability.
SUMMARY OF THE INVENTION
An object of this invention, therefore, is to overcome the
above-described difficulties in conventional liquid developers for
electrostatic photography. That is, the object of this invention is
to provide a liquid developer the redispersibility and stability of
which are not deteriorated by the storage of the developer for a
long period of time, nor by repeated use thereof.
Other object of this invention to provide a liquid developer which
does not cause problems in a developing apparatus, such as clogging
of liquid supply pumps, etc., or stain of images by the repeated
use of the developer.
A further object of this invention is to provide a liquid developer
which does not change polarity upon long storage or by repeated use
thereof and always reproduces clear images.
Still another object of this invention is to provide a liquid
developer having uniform particle size which provides excellent
resolving power at fine line portions and dot portions.
According to the results of various investigations, it has been
discovered that the above-described objects of this invention have
been attained by the present invention as set forth below.
That is, according to this invention, there is provided a liquid
developer for electrostatic photography comprising a carrier liquid
having an electric resistance of at least 10.sup.9
.OMEGA..multidot.cm and a dielectric constant of not more than 3.5,
and a resin dispersed therein, said resin being obtained by
polymerizing a monomer (A), which is soluble in the carrier liquid
but becomes insoluble upon being polymerized, in the presence of at
least one kind of a soluble dispersion stabilizing resin and said
soluble dispersion stabilizing resin being a copolymer containing
at least recurring units represented by formulae (IIIa) and (IIIb)
obtained by further applying a reaction for introducing an
unsaturated bond into a copolymer by polymerizing a monomer (B)
represented by general formula (I) and a monomer (C) represented by
general formula (II); ##STR2##
In formula (I), V represents --O--, --S--, --CO--, --CO.sub.2 --,
--SO.sub.2 --, --OCO--, --CONH--, --CONR' (wherein R' represents a
hydrocarbon group, preferably C.sub.1 to C.sub.6), --NHCO--,
--NHCO.sub.2 --, or --NHCONH--; X represents --CO.sub.2 H, --COCl,
--OH, --SH, --NH.sub.2, --NCO, or --SO.sub.2 CH.sub.2 CH.sub.2 Cl;
W represents a hydrocarbon group linking the atomic group V and the
atomic group X, which may be through a hetero atom, or W represents
a chemical bond; and a.sub.1, a.sub.2, and a.sub.3 (which may be
the same or different) each represents a hydrogen atom, a
hydrocarbon group (preferably C.sub.1 to C.sub.4), a carboxy group,
or a carboxy group through a hydrocarbon group.
In formula (II), Y represents --O--, --S--, --CO--, --CO.sub.2 --,
--SO.sub.2 --, --OCO--, --CONH--, --CONR"-- (wherein R" represents
a hydrocarbon group, preferably C.sub.1 to C.sub.6), --NHCO--,
--NHCO.sub.2 --, or --NHCONH--; R represents a hydrocarbon group
(preferably C.sub.1 to C.sub.6); and b.sub.1, b.sub.2, and b.sub.3
(which may be the same or different) each represents a hydrogen
atom, a hydrocarbon group (preferably C.sub.1 to C.sub.4), a
carboxy group, or a carboxy group through a hydrocarbon group.
In formula (IIIa), a.sub.1, a.sub.2, a.sub.3, V, and W have the
same meanings as defined for formula (I); X' represents --CO.sub.2
--, --COS--, --SCO--, --CONH--, --OCO--, --NHCO--, --NHCONH--,
--SO.sub.2 --, --O--, or --S--; Z represents a hydrocarbon group
for linking the atomic group X' to an unsaturated bond, which may
be through a hetero atom, or Z represents a chemical bond; the
total number of atoms of the main chain moiety of the atomic group
--V--W--X'--Z-- must be at least 9; and d.sub.1, d.sub.2, and
d.sub.3 (which may be the same or different) each represents a
hydrogen atom, a hydrocarbon group (preferably C.sub.1 to C.sub.4),
a carboxy group, or a carboxy group through a hydrocarbon
group.
In formula (IIIb), b.sub.1, b.sub.2, b.sub.3, Y and R have the same
meanings as defined for formula (II).
DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred carrier liquids having an electric resistance of at least
10.sup.9 .OMEGA..multidot.cm and a dielectric constant of not more
than 3.5 for use in this invention include straight-chain or
branched-chain aliphatic hydrocarbons and the halogen-substitution
products thereof. Examples of these materials are octane,
isooctane, decane, isodecane, decalin, nonane, dodecane,
isododecane, Isopar E, Isopar G, Isopar H, Isopar L (Isopar is a
trademark of Exxon Co.), Shellsol 70, Shellsol 71 (Shellsol is a
trademark of Shell Oil Co.), AMSCO OMS, AMSCO 460 solvent (AMSCO is
a trademark of Spirits Co.), etc., and they may be used solely or
as a mixture of them.
The resin (i.e., insoluble latex particles) for use in this
invention are prepared by a so-called dispersion polymerization
method using the soluble dispersion stabilizing resin and in this
case, a straight chain or branched aliphatic hydrocarbon, an
alicyclic hydrocarbon, an aromatic hydrocarbon or the
halogen-substitution products imiscible with the above-described
carrier liquid can be used as a solvent for the polymerization.
Examples of the solvent are octane, isooctane, decane, isodecane,
decalin, nonane, dodecane, isododecane, Shellsol 70, Shellsol 71,
AMSCO OMS, AMSCO 460 solvent. they may be used individually or as a
mixture thereof.
For stably obtaining the insoluble latex particles in such a
nonaqueous solvent, at least one kind of a copolymer containing
repeating units represented by formula (IIIa) and (IIIb) described
above is used. There is no particular restriction on the solvent
which is used at the preparation of the aforesaid copolymer, but
the solvent is preferably miscible with the solvent which is used
for the subsequent dispersion polymerization process, since the
copolymerization product can be used in the subsequent dispersion
polymerization process without need of removing the solvent from
the polymerization system. For example, straight chain or branched
aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic
hydrocarbons, and the halogen-substituted products thereof can be
used singly or as a mixture thereof.
As the monomer (B) represented by above-described formula (I), a
monomer in which the atomic group X as a reactive moiety of a
marcomolecular reaction for introducing an unsaturated bond is
apart from a polymerization active unsaturated bond and which has a
high activity is preferred. Examples of the monomer (B) are as
follows. ##STR3##
The chemical names of monomers B-(1) to B-(10) are as follows:
B-(1) 11-(Methacryloylamino)undecanoic acid
B-(2) 11-(Acryloyoamino)undecanoic acid
B-(3) 2-[(2-Methyl-1-oxo-2-propenyl)oxy]ethyl hydrogen
glutarate
B-(4) 2-[(1-Oxo-2-propenyl)oxy]ethyl hydrogen glutarate
B-(5) 2-[(1-Oxo-4-chloroformylbutyl)oxy]ethyl methacrylate
B-(6) 2-[(1-Oxo-4-chloroformylbutyl)oxy]ethyl acrylate
B-(7) 2-[(2-Methyl-1-oxo-2-propenyl)oxy]ethyl hydrogen
succinate
B-(8) 2-[(1-Oxo-2-propenyl)oxy]ethyl hydrogen succinate
B-(9) 2-Hydroxyethyl 11-(methacryloylamino)undecanate
B-(10) 2-[(2-Methyl-1-oxy-2-propenyl)oxy]ethyl 2-hydroxyethyl
succinate.
Also, the monomer (C) represented by above-described formula (II)
is for rendering the resin soluble and it is preferred that the
alkyl group R is in a state of easily miscible with the carrier
liquid having an electric resistance of at least 10.sup.9
.OMEGA..multidot.cm and a dielectric constant of not more than 3.5.
Examples of the monomer (C) include alkyl esters of acrylic acid or
methacrylic acid (the alkyl group includes, for example, an octyl
group, a decyl group, a dodecyl group, a tetradecyl group, a
hexadecyl group, an octadecyl group, a 2-ethylhexyl group, etc.,)
and alkenyl esters of acrylic acid or methacrylic acid (the alkenyl
group includes, for example, an octenyl group, a decenyl group, an
octadecenyl group, an oleyl group, etc.,).
As a reaction reagent which is used for introducing an unsaturated
bond by causing a reaction with the copolymer obtained by
polymerizing monomer (B) and monomer (C) as described above, there
are vinyl esters or allyl esters of aliphatic carboxylic acid (the
alkyl group includes a methyl group, an ethyl group, a butyl group,
a propyl group, an isopropyl group, etc.), unsaturated alcohols
(e.g., allyl alcohol), unsaturated carboxylic acid esters having a
hydroxy group, an amino group or a carboxy group at the alcohol
moiety of the ester (e.g., hydroxyethyl acrylate, hydroxypropyl
acrylate, etc.), unsaturated amines (e.g., allylamine), ethers
having unsaturated bond (e.g., butylvinyl ether), unsaturated
thiols, etc.
As the above-described monomer (A) for use in this invention, a
monomer which is soluble in the above-described carrier liquid and
nonaqueous solvent, but becomes insoluble therein by being
polymerized. Examples of such a monomer are alkyl esters (the alkyl
moiety having 1 to 3 carbon atoms) of unsaturated carboxylic acids
such as acrylic acid, methacrylic acid, crotonic acid, itaconic
acid, maleic acid, etc.; vinyl esters or allyl esters of aliphatic
carboxylic acids having from 1 to 3 carbon atoms; unsaturated
carboxylic acids such as acrylic acid, methacrylic acid, crotonic
acid, maleic acid, itaconic acid, etc., and the anhydrides thereof;
hydroxyethyl acrylate; hydroxyethyl methacrylate;
N-vinylpyrrolidone; acrylonitrile; vinyl ether, etc. The preferred
examples of the monomer (A) include a substance represented by the
following formula (IV), itaconic anhydride, maleic anhydride,
vinylpyrrolidone, and acrylonitrile; ##STR4##
In formula (IV), e.sub.1, e.sub.2 and e.sub.3 (which may be the
same or different) each represents a hydrogen atom, a hydrocarbon
group having 1 to 4 carbon atoms, a carboxy group, or a carboxy
group through a hydrocarbon group; L represents a hydrocarbon atom
having 1 to 2 carbon atoms, or L represents a chemical bond; M
represents --CO.sub.2 --, --OCO--, or --O--; and N represents a
hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms, or a
hydroxyl group through a hydrocarbon group.
The soluble copolymer resin having unsaturated bond, which is used
in this invention, is prepared by using the above-described
materials as follows.
Monomer (B) and monomer (C) are dissolved in the above-described
solvent and the solution is heated for several hours at 50.degree.
C. to 200.degree. C. in the presence of a polymerization initiator.
Then, a polymerization inhibitor (preferably, 0.01 to 1 g per liter
of the reaction mixture) and the above-described reactive reagent
for introducing unsaturated bond are added to the reaction mixture,
and after, if desired, further adding thereto a catalyst such as
Ti(OBu).sub.4.H.sub.2 SO.sub.4, Hg(OAc).sub.2.Me.sub.2 NC.sub.12
H.sub.25, (wherein, Bu represents butyl group, Ac acetyl group, and
Me methyl group), etc., the mixture is heated for several hours at
the same temperature as above. In this case, it is preferred that
the ratio of monomer (B) to monomer (C) used is 50/50 to 0.5/99.5
by mole ratio and the ratio of of monomer (B) to the reaction
reagent for introducing unsaturated bond is 2/3 to 2/1 by mole
ratio.
The molecular weight of the copolymer having unsaturated bond thus
obtained is from about 5,000 to about 500,000.
Then, specific examples of the copolymer having unsaturated bond
are illustrated below, but the invention is not limited to these
copolymers. ##STR5##
Next, the process of obtaining the dispersion of the granular resin
is explained. That is, a mixture of at least one kind of monomer
(A) described above and at least one kind of dispersion stabilizing
resin containing unsaturated bond obtained by the above-described
process is heated together with the aforesaid nonaqueous solvent in
the presence of a polymerization initiator to 50.degree. C. to
200.degree. C. for several hours. In this case, a conventional
stabilization stabilizer may be used. That is, various kinds of
synthetic or natural resins soluble in the nonaqueous solvent
employed can be used, singly or as a mixture thereof. Examples of
these resins are polymers of monomers such as arylic acid or
methacrylic acid alkyl esters having an alkyl chain having 4 to 30
carbon atoms, which may have a substituent such as a halogen atom,
a hydroxy group, an amino group, an alkoxy group, etc., or which
may have a main chain, carbon-carbon bond by a hetero atom such as
an oxygen atom, a nitrogen atom, a sulfur atom, etc.), vinyl esters
of fatty acids, vinyl alkyl ethers, or olefins such as butadiene
isoprene, diisoprene, etc., copolymers of two or more monomers
described above, and copolymers of the various monomers for forming
the above-described polymers soluble in the nonaqueous solvent and
at least one of the following various monomers, said copolymers
being soluble in the nonaqueous solvent. Examples of such a monomer
are vinyl acetate; methyl, ethyl, n-propyl or iso-propyl esters of
acrylic acid, methacrylic acid or crotonic acid; styrene or styrene
derivatives such as vinyltoluene, .alpha.-methylstyrene, etc.;
unsaturated carboxylic acids such as acrylic acid, methacrylic
acid, crotonic acid, maleic acid, itaconic acid, etc., or the
anhydrides thereof; and monomers having various polar groups such
as a hydroxy group, an amino group, an amido group, a cyano group,
a sulfonic acid group, a carbonyl group, a halogen atom, a
heterocyclic ring, etc., e.g., hydroxyethyl methacrylate,
hydroxyethyl acrylate, diethylaminoethyl methacrylate,
N-vinylpyrrolidone, acrylamide, acrylonitrile, 2-chloroethyl
methacrylate, 2,2,2-trifluoroethyl methacrylate, etc. In addition
to the above-described synthetic resin, an alkyd resin, an alkyd
resin modified by various kinds of fatty acids, linseed oil, or a
denatured polyurethane resin can be used. In this case, at least
one kind of monomer (C) represented by formula (II), which is not
solubilized in the aforesaid carrier liquid and nonaqueous solvent
even by being polymerized, can be used together with aforesaid
monomer (A).
Monomers (A) may be used singly or as a mixture thereof but the
total amount thereof is 5 to 80 parts by weight, and preferably
from 10 to 50 parts by weight, per 100 parts by weight of the
aforesaid nonaqueous solvent which is a reaction solvent. In the
case of using monomer (C), the total amount is from 0.1 to 50 parts
by weight, and preferably from 0.5 to 20 parts by weight, per 100
parts by weight of the above-described whole monomers (A).
The amount of the dispersion stabilizing resin described above is
from 1 to 100 parts by weight, and preferably 5 to 50 parts by
weight, per 100 parts by weight of the aforesaid whole monomers
(A).
The proportion of the polymerization initiator for use in the
aforesaid method is generally from 0.1 to 5 parts by weight per 100
parts by weight of the total monomers.
The nonaqueous dispersion resin prepared by the above process has a
uniform and mono-dispersed particle distribution and the particle
size thereof can be desirably controlled. These dispersed resins
have very good redispersibility, stabilization, and fixability.
Thus, by using the liquid developer composed of the above-described
materials, troubles of precipitation, aggregation, sticking stains,
etc., on various portions of developing apparatus or vessels do not
occur by the storage thereof for a long period of time or by the
repeated use thereof, with strong films being formed by performing
fixing by heating, etc., and images having high durability are
formed. It can be considered that the above-described remarkable
improvement of performance is obtained by the following aspects of
this invention.
Hitherto, in a conventional resin dispersed in a nonaqueous carrier
liquid, there has been a disadvantage that when the liquid
developer is stored for a long period of time or is used
repeatedly, the soluble dispersion stabilizing resin used is
released from the insoluble latex particles, to deteriorate the
performance thereof. For eliminating the problems caused thereby, a
means as disclosed in U.S. Pat. No. 3,990,980 has been proposed, as
described hereinbefore. However, even by the means disclosed in
aforesaid U.S. Pat. No. 3,990,980, the improvement of the liquid
developer is insufficient and it is considered that the portion of
the total soluble dispersion stabilizing resins irreversibly bonded
to the insoluble latex particles is very slight. In this invention,
however, a remarkable improvement in the performance of the liquid
developer is obtained by separating new unsaturated bond introduced
into the soluble dispersion stabilizing resin by the reaction for
introducing the unsaturated bond from the main chain of the resin
to some extent (more than 9 carbon atoms of the main chain moiety
of the linkage group) and it is considered to be based on the
reduction in steric hindrance at the case of graft polymerizing the
aforesaid monomer (A) to the soluble dispersion stabilizing
resin.
In this invention, if desired, coloring agents may be used. There
is no particular restriction on the coloring agents, and
conventional pigments or dyes can be used in this invention. The
coloring may be used dispersed in the aforesaid nonaqueous solvent
solely or together with a dispersion accelerator, etc., or may be
used as graft type particles (e.g., Graft Carbon, trademark for
product, made by Mitsubishi Gas Chemical Company, Ltd.) formed by
chemically bonding a polymer to the surface of a coloring agent.
The coloring agent may be also incorporated in the afresaid
resin.
As a method of coloring the aforesaid resin dispersed, one useful
method involves physical dispersion in the resin using a dispersing
means (e.g., a paint shaker, a colloid mill, a vibration mill, a
ball mill, etc.) as described, for example, in Japanese Patent
Application (OPI) No. 75242/73, etc. Examples of pigments and dyes
which are used for the purpose in this invention are magnetic iron
oxide powder, carbon black, nigrosine, alkali blue, Hansa Yellow,
Quinacridone Red, Phthalocyanine Blue, Phthalocyanine Black,
Benzidine Yellow, etc.
In another method, the colored resin particles can be produced by
adding at least one kind of an organic dye directly or as the
solution thereof in the dispersion containing the resin particles,
and then adding thereto a second solvent which is miscible with the
nonaqueous solvent and can at least swell the resin particles,
followed by heating.
For example, the resin particles can be dyed using a dye having a
solubility in a monomer which is a component for constituting the
copolymer sparingly soluble or insoluble in the nonaqueous solvent
upon heating. In this case, if desired, the aforesaid second
solvent may be present in the system.
In this case, it is considered that the copolymer particles are
dyed by impregnating the copolymer particles with a dye used or by
adhering the dye to the copolymer particles.
Accordingly, it is preferred to select an optimum dye for dyeing
according to the components for constituting the copolymer
particles.
Examples of such dyes are disperse dyes such as dyes for dyeing
polyester, polyacrylic resins, polyacrylonitrile resins, etc.
Specific examples of these dyes are Celliton Fast Yellow RR,
Kayalon Fast Yellow G, Kayalon Fast Brown R, Kayalon Fast Scarlet
B, Celliton Fast Rubine 3B, Celliton Fast Scarlet R, Kayalon Fast
Rubine B, Kayalon Fast Red R, Miketon Fast Pink FR, Kayalon Fast
Violet BB, Miketon Fast Violet BB, Kayalon Fast Blue FN, Kayalon
Fast Blue Greem B, Sumikaron Yellow FG, Sumikaron Blue BR,
Sumikaron Navy Blue R, etc. (with respect to the aforesaid
products, Calliton is a trademark for products made by BASF;
Kayalon is a trademark for products made by Nippon Kayaku Co.,
Ltd.; Miketon is a trademark for products made by Mitsui Chemical
Co., Ltd.; and Sumikaron is a trademark for products made by
Sumitomo Chemical Company, Limited).
Other examples of the dyes are basic dyes. Specific examples of the
basic dyes are Flavine 8G, Auramine, Crystal Violet, Methylene
Blue, Rhodamine 6G, Malachite Green, Sumiacryl yellow 3G, Sumiacryl
Yellow 3R, Sumiacryl Organge G, Sumiacryl Orange R, Aizen Cathilon
Pink, Aizen Cathilon Red 6BH, Aizen Basic Cyanine 6GH, Primocyanine
BX, etc., (in the above products, Sumiacryl is a trademark for
products made by Sumitomo Chemical Company, Limited; and Aizen
Cathilon is a trademark for products made by Hodogaya Chemical Co.,
Ltd.). Furthermore, the dyes described in Masao Iizuka, Senryo
Kogaku (Dyeing Industry), Vol. 13, pp. 429-448(1965) can be used in
this invention.
A second solvent which can be used, if desired, capable of
dissolving the dye, miscible with the non-aqueous solvent, and
capable of at least swelling the resin particles is suitably any
monomers used as a component for constituting the resin. The use of
such a monomer has advantages in that adverse influences such as
the dissolution or aggregation of the resin particles occuring in
the case of using other solvents do not occur. However, ethanol,
acetone, ethyl acetate, etc., which satisfy the above-described
conditions, can be used by carefully controlling the amount
thereof.
When a sufficient amount of a monomer residue remains in the case
of forming the resin particles by for example, the above-described
polymerization granulation method, it is unnecessary to add the
second solvent to the dispersion of the resin particles, but when
the amount of the monomer residue is small, it is necessary to add
the second solvent to the dispersion so that the total amount of
the monomer and the second solvent becomes at least one-tenth
(1/10th) of the weight of the resin particles in the
dispersion.
The second solvent may be added to the resin particle dispersion as
a solution of the solvent having dissolved therein a dye, or may be
added to the dispersion before or after adding the dye as a powder
to the dispersion.
In any case, it is necessary that the dye(s) and the second solvent
exist in the resin particle dispersion at the subsequent stage of
removing the second solvent from the dispersion. However, the
addition of the dye(s) and the second solvent is not always
finished before the subsequent state of removing the second solvent
and, for example, the dye(s) and/or the second solvent may be
supplied to the dispersion while removing the second solvent. Also,
the proportion of the second solvent is from about 0.1 to 10 times
the weight of the resin particles in the dispersion, but since the
solvent is removed under reduced pressure in the subsequent step,
it is preferred that the amount of the second solvent is not over
1/3 of the volume of the resin particle dispersion.
However, the amount of the second solvent is not limited to the
aforesaid range, since an optimum addition ratio may exist outside
the aforesaid range according to the particular kinds of the
dye(s), resin particles, nonaqueous solvent, and second solvent
used.
Thus, during or after adding the dye(s) and the second solvent to
the dispersion, the removal of the second solvent is performed. The
removal of the second solvent is performed by subjecting the
dispersion containing the dye(s) and the second solvent to a
reduced pressure or by heating the dispersion while subjecting the
dispersion to a reduced pressure.
The amount of the dye(s) may be 0.5% by weight or more of the
amount of the resin particles in the dispersion, but is preferably
3% by weight or more for obtaining good color density. There is no
particular restriction on the maximum amount of the dye(s), but the
amount thereof is usually not more than 20% by weight.
The heating temperature for dyeing is usually from 40.degree. C. to
150.degree. C., and preferably from 80.degree. C. to 150.degree. C.
Also, the heating time period is from 30 minutes to 12 hours, and
preferably from 1 hour to 5 hours.
Mordant dyeing is another method for dyeing the dispersed resin
particles. In this method, the dispersed resin particles can be
dyed using a basic dye (cationic dye) when at least one component
constituting the dispersed resin particles contains an acid group
(e.g., carboxy group) or using an acid dye when at least one
component constituting the resin particles contains a basic group.
This method is based on so-called ionic bonding between the acid
group and the basic group.
As the basic dyes for the above-described resin particles composed
of the copolymer containing carboxy group, there are Aizen Victoria
Blue BH, Aizen Victoria Pure Blue BOH, Aizen Cathilon Grey BLH,
Aizen Cathilon Black GH (trademark for product made by Hodogaya
Chemical Co., Ltd.), etc., in addition to the above-described basic
dyes.
On the other hand, the acid dyes for dyeing the resin particles
composed of the copolymer containing a basic group are acid dyes
containing carboxy group or a sulfonic acid group and examples of
these dyes include Kiton Blue A (trademark for product made by Ciba
Corp.), Alizarine Astrol B (trademark for product made by Ikeda
Kagaku K.K.), Kayanol Blue N 2G (trademark for product made by
Nippon Kayaku Co., Ltd.), Kayacyl Blue BR (trademark for product
made by Nippon Kayaku Co., Ltd.), Suminol Fast Sky Blue B
(trademark for product made by Sumitomo Chemical Company, Limited),
Alizaline Light Brown BL (trademark for made by Mitsubishi Chemical
Industries, Ltd.), Aizen Eosine GH (trademark for product made by
Hodogaya Kagaku Co., Ltd.), Alizarinol R (trademark for product
made by Yamada Kagaku K.K.), etc.
If desired, the carboxy group or the sulfonic acid group of these
acid dyes may be converted into the form of a free acid, the form
of a metal salt of an organic base, or the form of a quaternary
ammonium salt.
The amount of the dye(s) used and the dyeing condition are same as
those in the above-described physical dyeing.
These dispersed resin particles have very good redispersibility,
stability, and fixability.
The liquid developer of this invention may further contain, if
desired, various additives for improving charge characteristics,
improving image quality, etc., and practical additives are
described, for example, in Yuji Harasaki, Denshi Shashin
(Electrophotography), Vol. 16, No. 2, page 44 (1978).
Specific examples of such additives are
di-2-ethylhexylsulfosuccinic acid metal salts, naphthenic acid
metal salts, higher resin acid metal salts, lecithin,
poly(vinylpyrrolidone), etc.
The amounts of the main components of the liquid developer of this
invention are described as follows.
The amount of the insoluble latex particles composed of the resin
and the coloring agent as the main components is preferably from
about 0.5 to 50 parts by weight per 1,000 parts by weight of the
carrier liquid. If the amount is less than 0.5 part by weight, the
image density becomes deficient, while if the amount is above 50
parts by weight, fog is liable to form at non-imaged portions. The
resin soluble in the carrier liquid such as the above-described
dispersion stabilizing agent, etc., is used, if desired, and the
amount thereof is preferably from about 0.5 to 100 parts by weight
per 1,000 parts by weight of the carrier liquid.
The amount of the charge controlling agent as described above is
preferably from about 0.001 to 1.0 part by weight per 1,000 parts
by weight of the carrier liquid. Furthermore, the liquid developer
may further contain various additives and the upper limit of the
total amounts of these additive is regulated by the electric
resistance of the liquid developer. That is, if the electric
ressistance of the liquid developer in a state of not containing
the insoluble latex particles is lower than 10.sup.9
.OMEGA..multidot.cm, images having good continuous gradation is
reluctant to obtain and hence the addition amounts of these
additives must be controlled in the range of not lowering the
electric resistance below 10.sup.9 .OMEGA..multidot.cm.
Some embodiments for producing resins or resin particles for use in
this invention are described below, but it should be understood
that the scope of this invention is not limited to these
embodiments.
PRODUCTION EXAMPLE 1
Production of soluble dispersion stabilizing resin (Compound
(i))
A mixed solution composed of 96.7 g of lauryl methacrylate, 5.4 g
of monomer B-(1), and 100 g of toluene was heated to 70.degree. C.
under nitrogen gas stream and 1.0 g of azobisisobutyronitrile was
added thereto with stirring. After 6 hours since then, the mixture
was cooled to 40.degree. C. and 0.2 g of hydroquinone was added
thereto.
Then, after further adding thereto 6.9 g of vinyl acetate and 0.05
g of mercury acetate, the reaction was performed for 2 hours. The
temperature of the mixture was increased again to 70.degree. C.,
and after further adding thereto 7.5.times.10.sup.-3 ml of 100%
sulfuric acid, the reaction was performed until the determination
value of the carboxylic acid originated in monomer B-(1) was
reduced to 50%.
After the reaction was over, 0.04 g of sodium acetate trihydrate
was added to the reaction mixture followed by thorough stirring
4,000 g of methanol was added to the reaction mixture to perform
reprecipitation and purification, whereby a brownish viscous
product was obtained. The mean molecular amount of the viscous
product measured by a high-speed liquid chromatograph method was
14.5.times.10.sup.4.
PRODUCTION EXAMPLE 2
Production of soluble dispersion stabilizing resin (Compound
(ii))
By following the same procedure as in Example 1, except for using
128.6 g of stearyl methacrylate in place of lauryl methacrylate, a
yellowish powder product was obtained. The mean molecular weight
measured as in Example 1 was 22.2.times.10.sup.4.
PRODUCTION EXAMPLE 3
Production soluble dispersion stabilizing resin (Compound
(iii))
A mixed solution composed of 87.5 g of lauryl acrylate, 9.7 g of
monomer B-(1), and 120 g of Isoper E was heated to 80.degree. C.
under nitrogen gas stream and the 1.0 g of azobisisobutyronitrile
was added thereto while stirring. 3 hours later, 1.0 g of
azobisisobutyronitrile was added thereto, and reaction was further
conducted for another 3 hours. Then, after adding thereto 0.2 g of
hydroquinone, 11.4 g of vinyl acetate and 1.0 g of tetrabutoxy
titanium were added to the mixture and then the reaction was
performed until the determination value of the carboxylic acid
orginated in monomer B-(1) was reduced to 50%. After the reaction
was over, the reaction product was reprecipitapted from 4,000 g of
acetonitrile, to provide a brownish viscous product. The mean
molecular weight of the product was 10.3.times.10.sup.4.
PRODUCTION EXAMPLE 4
Production of soluble dispersion stabilizing resin (Compound
(iv))
A mixed solution composed of 137.1 g of stearyl methacrylate, 11.0
g of monomer B-(3), and 300 g of toluene was heated to 70.degree.
C. under a nitrogen gas stream, and then 1.5 g of
azobisisobutyronitrile was added thereto with stirring. 6 hours
later, the mixture was cooled to 40.degree. C. and 0.5 g of
hydroquinone was added to the mixture. Then, after further adding
thereto 31.0 g of vinyl acetate and 0.2 g of mercury acetate,
reaction was performed for another 2 hours. The temperature of the
mixture was increased again to 70.degree. C., and after further
adding thereto 3.4.times.10.sup.2 ml of 100% sulfuric acid,
reaction was performed until the determination value of the
carboxylic acid originated in monomer B-(3) was reduced to 35%.
After the reaction was over, 0.2 g of sodium acetate trihydrate was
added to the reaction mixture followed by stirring well and then,
the reaction mixture was reprecipitated and purified as in
Production Example 1 to provide a white powder product. The mean
molecular weight of the product was 29.5.times.10.sup.4.
PRODUCTION EXAMPLE 5
Production of soluble dispersion stabilizing resin (Compound
(v))
A mixed solution composed of 162.0 g of hexadecyl methacrylate, 6.7
g of monomer B-(3), and 200 g of Iospar E was heated to 70.degree.
C. under a nitrogen gas stream and then 1.6 g of
azobisisobutyronitrile was added thereto while stirring. 6 hours
later, 0.2 g of hydroquinone was added to the mixture. Then, the
temperature of the mixture was raised to 80.degree. C. and after
adding thereto 25.0 g of vinyl acetate and 3 g of tetrabutoxy
titanium, the reaction was performed until the determination value
of the carboxylic acid originated in the monomer B-(3) was reduced
to 50%. After the reaction was over, the reaction product was
reprecipitated and purified as in production Example 3, to provide
a slightly yellowish viscous product. The mean molecular weight of
the product was 28.7.times.10.sup.4.
PRODUCTION EXAMPLE 6
Production of soluble dispersion stabilizing resin (Compound
(viii))
A mixed solution composed of 137.1 g of stearyl methacrylate, 11.0
g of monomer B-(3), and 200 g of Isopar G was heated to 80.degree.
C. under nitrogen gas stream and then 1.4 g of
azobisisobutyronitrile was added thereto with stirring. 6 hours
later, 0.1 g of hydroquinone was added to the mixture. Then, after
raising the temperature thereof to 110.degree. C., 10.0 g of allyl
alcohol and 0.5 g of concentrated sulfuric acid were added to the
mixture and the reaction was performed while removing water
distilled out in the reaction by Dean-Stark means. The reaction was
stopped when the determination value of the carboxylic acid
originated in the monomer B-(3) was reduced to 35% and then the
reaction mixture was reprecipitated and purified as in Production
Example 3, to provide a white powder product. The mean molecular
weight was 24.9.times.10.sup.4.
PRODUCTION EXAMPLE 7
Production of soluble dispersion stabilizing resin (Compound
(ix))
A mixed solution composed of 105.6 g of hexadecyl acrylate, 64.7 g
of monomer B-(1), and 400 g of Isopar G was heated to 80.degree. C.
under nitrogen gas stream and then 1.6 g of azobisisobutyronitrile
was added to the mixture while stirring. 6 hours later, 0.1 g of
hydroquinone was added to the mixture. After raising the
temperature of the mixture to 110.degree. C., 58.1 g of allyl
alcohol and 0.5 g of concentrated sulfuric acid were added thereto,
and then the reaction was performed while removing water distilled
out from the mixture by Dean-Stark means. The reaction was stopped
when the determination value of the carboxylic acid originated in
the monomer B-(1) was reduced to 35% and the reaction mixture was
reprecipitated and purified as in Production Example 3 to provide a
slightly brownish viscous product. The mean molecular weight of the
product was 19.7.times.10.sup.4.
RESIN PARTICLE PRODUCTION EXAMPLE 1
A mixture composed of 13.2 g of the resin obtained by Production
Example 1 for soluble dispersion stabilizing resin, 110 g of vinyl
acetate, and 440 g of Isoper H was heated to 70.degree. C. under a
nitrogen gas stream and then 1.1 g of azobisisovaleronitrile was
added to the mixture while stirring. About 40 minutes after the
additon of the polymerization initiator, the reaction mixture began
to become turbid white and the temperature increased to 85.degree.
C. 2 hours later, 0.6 g of azobisisovaleronitrile was further added
to the mixture and then reaction was further performed for another
2 hours. After cooling, the reaction mixture was filtered through a
cloth of 200 mesh to provide a white dispersion as a latex having a
polymerization ratio of 88% and a mean particle size of 0.21
micron.
RESIN PARTICLE PRODUCTION EXAMPLE 2
A mixture composed of 24 g of the resin obtained in Production
Example 2 for soluble dispersion stabilizing resin, 120 g of vinyl
acetate, and 680 g of isodecane was heated to 70.degree. C. under a
nitrogen gas stream, and then 1.2 g of azobisisobutyronitrile was
added thereto white stirring. After performing reaction for 6
hours, the reaction mixture was cooled and filtered through a cloth
of 200 mesh to provide a white dispersion as a latex having a
polymerization ratio of 83% and a mean particle size of 0.16
micron.
RESIN PARTICLE PRODUCTION EXAMPLE 3
A mixture composed of 33.6 g of the resin obtained in Production
Example 4 for soluble dispersion stabilizing resin, 240 g of vinyl
acetate, and 960 g of Isopar H was added to 70.degree. C. under
nitrogen gas stream and then 1.9 g of azobisisovaleronitrile was
added to the mixture while stirring. After 2 hours, 0.9 g of
azobisisovaleronitrile was further added to the mixture, and then
the reaction was further performed for another 4 hours. After
cooling, the reaction mixture was filtered through a cloth of 200
mesh to provide a white dispersion as a latex having a
polymerization ratio of 85% and a mean particle size of 0.19
micron.
RESIN PARTICLE PRODUCTION EXAMPLE 4
A mixture composed of 60 g of the resin obtained in Production
Example 6 for soluble dispersion stabilizing resin, 240 g of vinyl
acetate, and 560 g of isodecane was heated to 70.degree. C. under
nitrogen gas stream and then 2.4 g of azobisisobutyronitrile was
added thereto under stirring. After performing reaction for 7
hours, the reaction mixture thus obtained was cooled and filtered
through a cloth of 200 mesh to provide a white dispersion as a
latex having a polymerization ratio of 81% and a mean particle size
of 0.15 micron.
RESIN PARTICLE PRODUCTION EXAMPLE 5
The same procedure as foregoing Production Example 3 was followed
by further adding 7.2 g of crotonic acid to the mixture used in the
production example. After cooling, the reaction mixture thus
obtained was filtered through a cloth of 200 mesh to provide a
white dispersion as a latex having a polymerization ratio of 80%
and a mean particle size of 0.15 micron.
RESIN PARTICLE PRODUCTION EXAMPLE 6
The same procedure as foregoing Production Example 4 of resin
particles was followed by further adding 7.2 g of crotonic acid to
the mixture used in the production example. After cooling, the
reaction mixture thus obtained was filtered through a cloth of 200
mesh to provide a white dispersion as a latex having a
polymerization ratio of 78% and a mean particle size of 0.12
micron.
RESIN PARTICLE PRODUCTION EXAMPLE 7
A mixture composed of 37.5 g of the resin obtained in Production
Example 7 for soluble dispersion stabilizing resin, 125 g of vinyl
acetate, 3.7 g of crotonic acid, and 230 g of isodecane was heated
to 70.degree. C. under a nitrogen gas stream, and then 1.2 g of
azobisisobutyronitrile was added thereto while stirring. 2 hours
later, 0.6 g of azobisisobutyronitrile was further added to the
mixture and reaction was further performed for 4 hours. After
cooling, the reaction mixture thus obtained was filtered through a
cloth of 200 mesh to provide a white dispersion as a latex having a
polymerization ratio of 79% and a mean particle size of 0.14
micron.
RESIN PARTICLE PRODUCTION EXAMPLE 8
(Comparison Example A)
A mixed solution composed of 194 g of lauryl methacrylate, 6 g of
glycidyl methacrylate, and 400 g of isodecane was heated to
80.degree. C. under nitrogen gas stream and then 3.6 g of benzoyl
peroxide was added to the mixture under stirring. 4 hours later,
0.1 g of hydroquinone was added thereto, and after adding 0.5 g of
lauryldimethylamine and 3 g of methacrylic acid thereto, the
reaction was performed until 40% of the glycidyl group formed
methacrylic acid and ester. After the reaction was over, the
reaction mixture was purified by being reprecipitated from 4,000 g
of acetonitrile to provide a slightly brownish viscous product.
Then, a mixture composed of 36 g of the aforesaid viscous product,
200 g of vinyl acetate, 6 g of crotonic acid, and 470 g of
isodecane was heated to 70.degree. C. under a nitrogen gas stream
and then 2 g of azobisisobutyronitrile was added to the mixture
while stirring. After performing the reaction for 6 hours, the
reaction mixture thus obtained was cooled and filtered through a
cloth of 200 mesh to provide a white dispersion as a latex having a
polymerization ratio of 78% and a mean particle size of 0.12
micron.
RESIN PARTICLE PRODUCTION EXAMPLE 9
(Comparison Example B)
A mixed solution composed of 124 g of hexadecyl methacrylate, 8.6 g
of methacrylic acid, and 350 g of isodecane was heated to
80.degree. C. under a nitrogen gas stream, and then 3.0 g of
benzoyl peroxide was added to the mixture under stirring. 4 hours
later, 0.1 g of hydroquinone was added thereto and after adding
thereto 0.5 g of lauryldimethylamine and 21.3 g of glycidyl
methacrylate, reaction was performed until the determination value
of the carboxylic acid originated in methacrylic acid was reduced
to 20%. After the reaction was over, the reaction mixture was
purified by being reprecipitated from 5,000 g of acetonitrile to
provide a slightly brownish viscous product.
Then, a mixture composed of 60 g of the viscous product obtained in
the above step, 200 g of vinyl acetate, 8.1 g of maleic acid, and
470 g of isodecane was heated to 70.degree. C. under a nitrogen gas
stream and then 2 g of azobisisobutyronitrile was added to the
mixture while stirring. After performing the reaction for 6 hours,
the reaction mixture thus obtained was cooled and filtered through
a cloth of 200 mesh to provide a white dispersion as a latex having
a polymerization ratio of 75% and a mean particle size of 0.23
micron.
The following examples are intended to illustrate the present
invention, but not to limit it in any way.
EXAMPLE 1
In a paint shaker (made by Tokyo Seiki K.K.) 10 g of poly(lauryl
methacrylate), 10 g of Nigrosine, and 30 g of Shell Sol 71 were
placed together with glass beads, and the mixture was dispersed for
90 minutes to provide a fine dispersion of Nigrosine. Then, by
diluting 30 g of the resin dispersion of Resin Particle Production
Example 1, 25 g of the Nigrosine dispersion obtained in the above
step, and 0.05 g of zirconium naphthenate with one liter of Shell
Sol 71, a liquid developer was prepared.
(Comparison Liquid Developers A and B)
Furthermore, by following the same procedure as above except that
the following resin particles were used in place of the resin
dispersion used in the aforesaid process, two kinds of Comparison
Liquid Developers A and B were prepared.
Comparison Liquid Developer A; Using the resin dispersion of Resin
Particle Production Example 8.
Comparison Liquid Developer B: Using the resin dispersion by Resin
Particle Production Example 9.
Then, by using each of the liquid developers thus obtained as a
developer for a Fuji Automatic Electrophotographic Printing
Plate-Making Machine ELP 280 (made by Fuji Photo Film Co., Ltd.)
and also ELP masters (made by Fuji Photo Film Co., Ltd.) as an
electrophotographic light-sensitive material for printing master,
images were formed on the ELP master from positive originals having
a continuous gradation to provide each master plate. The images of
the master plates thus obtained were good. After processing 2,000
ELP masters, the presence of sticking of the toners to the
developing device and the presence of contamination were
observed.
The results showed that the liquid developer of this invention
using the resin particles (prepared by Resin Particle Production
Example 1) caused no contamination but two kinds of comparison
liquid developers A and B caused great sticking and contamination
at the peripheries of rollers. This clearly shows that resin
particles obtained by using the resins in which the distance
between the main chain and the unsaturated bond in the soluble
dispersion stabilizing resins is less than 9 atoms (the number of
atoms is 7 in both the comparison examples, niz., Resin Particle
Production Examples 8 and 9, respectively) are different from the
resin particles in this invention.
In the offset printing master plates obtained using the liquid
developer of this invention, the master plate obtained by the first
development process as well as the master plate obtained after
developing 2,000 masters by the final development process had very
clear images. Furthermore, when printing was conducted in an
ordinary manner using each of the masters obtained using the liquid
developer of this invention, clear prints could be obtained even
after printing 3,000 copies. Furthermore, when the same processing
as above was performed after allowing the liquid developer to stand
for 3 months, the results were exactly the same as those obtained
by using the developer before storage.
EXAMPLE 2
A mixture of 100 g of the white dispersion obtained in Resin
Particle Production Example 1 and 1.5 g of Sumikaron Black was
heated to 100.degree. C. and stirred for 4 hours at the
temperature. After cooling the mixture to room temperature, the
reaction mixture was filtered through a nylon cloth of 200 mesh to
remove the remaining dye, whereby a black resin dispersion having a
mean particle size of 0.21 micron was obtained.
Then, by dilusting a mixture of 30 g of the aforesaid black resin
dispersion and 0.05 g of zirconium naphthenate with one liter of
Shell Sol 71, a liquid developer was obtained.
When, the development was performed by means of the apparatus as in
Example 1 using the liquid developer thus obtained, no attachment
of toners to the apparatus was observed after developing 2,000
masters.
EXAMPLE 3
A mixture composed of 100 g of the white dispersion obtained in
Resin Particle Production Example 3 and 3 g of Victoria Blue B was
heated to 70.degree. C. to 80.degree. C. and stirred for 6 hours at
the same temperature. After cooling to room temperature, the
reaction mixture was filtered through a nylon cloth of 200 mesh to
remove the remaining dyes, whereby a blue resin dispersion having a
mean particle size of 0.20 micron was obtained.
By diluting a mixture of 28 g of the above-described blue resin
dispersion and 0.05 g of zirconium naphthenate with one liter of
Isopar H, a liquid developer was prepared.
When the development was performed by means of the apparatus as in
Example 1 using the liquid developer prepared above, no sticking of
toners to the apparatus was observed even after developing 2,000
masters. The image of the offset printing master plates thus
obtained were clear in each case, and the images of the print were
very clear even after printing 3,000 copies.
EXAMPLE 4
By diluting a mixture of 30 g of the white resin dispersion
obtained in Resin Particle Production Example 2, 2.5 g of the
Nigrosine dispersion obtained in Example 1, and 0.02 g of a half
docosanylamid product of a copolymer of diisobutylene and maleic
anhydride with one liter of Isopar G, a liquid developer was
obtained.
When the development was performed by means of the apparatus as in
Example 1 using the liquid developer prepared above, no sticking of
toners to the apparatus was observed even after developing 2,000
masters. Also, the images of the offset printing master plates thus
obtained as well as the images of the print after printing 3,000
copies were clear.
Furthermore, when the liquid developer was allowed to stand for 3
months and then the same processing as above was performed using
the developer, the results were exactly the same as those before
the storage thereof.
EXAMPLE 5
A mixture composed of 40 g of the white dispersion obtained in
Resin Particle Production Example 3, 8 g of Kayalon Fast Blue and
40 g of vinyl acetate was heated to 100.degree. C. and stirred for
2 hours at the same temperature. Thereafter, the reflux condensor
was removed and the solvent was distilled off by heating the
mixture for 3 hours while stirring. After cooling to room
temperature, the reaction mixture thus obtained was filtered
through a nylon cloth of 200 mesh to remove the remaining dye,
whereby a blue resin dispersion having a mean particle size of 0.20
micron was obtained. Then, by diluting a mixture of 30 g of the
aforesaid blue resin dispersion and 0.03 g of a half octadecylamide
copolymer of 1-octadecene and maleic acid with one liter of Shell
Sol 71, a liquid developer was prepared.
When the development by means of the apparatus as in Example 1
using the liquid developer, no sticking of toners to the apparatus
was observed even after developing 2,000 masters.
EXAMPLE 6
A mixture composed of 30 g of the white dispersion obtained in
Resin Particle Production Example 5, 1 g of Aizen Basic Cyanine and
3 g of ethanol was heated to 80.degree. C. and stirred for 2 hours
at the same temperature. Thereafter, the reflux condensor was
removed and the solvent was distilled off by stirring the mixture
for 3 hours at the same temperature. After cooling to room
temperature, the reaction mixture thus obtained was filtered
through a nylon cloth of 200 mesh to remove the remaining dye,
whereby a blue resin dispersion having a mean particle size of 0.16
micron was obtained. Then, by diluting a mixture of 30 g of the
aforesaid blue resin dispersion and 0.04 g of a copolymer of
diisobutylene and half maleic acid octadecylamide with one liter of
Shell Sol 71, a liquid developer was obtained.
When the development was performed by means of the apparatus as in
Example 1 using the aforesaid liquid developer, no sticking of
toners to the apparatus was observed even after developing 2,000
masters. Also, the images of the offset printing master plates thus
obtained were clear and the images of the print after printing
3,000 copies were also very clear.
EXAMPLE 7
By following the same procedure as in Example 3 except that 30 g of
the white dispersion obtained in Resin Particle Production Example
6 was used in place of 30 g of the white dispersion by Resin
Particle Production Example 5 used in Example 3, a liquid developer
was prepared.
When the development was performed by means of the apparatus as in
Example 1 using the liquid developer thus prepared, no sticking of
toners to the apparatus was observed even after developing 2,000
masters. Also, the images of each offset printing master thus
obtained and the images of the print after printing 3,000 copies
were all clear.
Furthermore, when the same processing as above was performed after
allowing the developer to stand for 3 months, the results were
exactly the same as those obtained by using the liquid developer
before the storage.
EXAMPLE 8
A mixture composed of 50 g of the white dispersion obtained in
Resin Particle Production Example 7, 0.3 g of Kayalon Fast Brown,
0.1 g of Miketon Fast Pink, 0.6 g of Victoria Blue, and 10 g of
vinyl acetate was heated to 100.degree. C. and stirred for 2 hours
at the same temperature. Thereafter, the reflux condenser was
removed, and the solvent was distilled off by stirring the mixture
for 3 hours at the same temperature. After cooling to room
temperature, the reaction mixture thus obtained was filtered
through a nylon cloth of 200 mesh to remove the remaining dyes,
whereby a black resin dispersion having a mean particle size of
0.15 micron was obtained.
By diluting a mixture of 30 g of the aforesaid black resin
dispersion and 0.05 g of zirconium naphthenate with one liter of
Shell Sol 71, a liquid developer was prepared.
When the development was performed by means of the apparatus as in
Example 1 using the liquid developer thus prepared, no sticking of
toners to the apparatus was observed even after developing 2,000
master plates. Also, the images of each offset printing master
plate and the images of the print after printing 3,000 copies were
all very clear.
While the invention has been described in detail and with reference
to specific embodiments thereof, it will be apparent to one skilled
in the art that various changes and modifications can be made
therein without departing from the spirit and scope thereof.
* * * * *